The Northwestern University Clinical Trials Unit (NU-CTU) is an existing and very productive clinical unit within the AIDS Clinical Trails Group. The NU-CTU has been invited to participate in the current ACTG application for a Network which will focus on translational research/drug development, optimization of clinical management including co-morbidities, vaccine research and development, prevention of mother-to-child transmission and prevention of HIV infection. The NU-CTU consists of 5 individual clinical research sites (CRS) operating under the Northwestern University administrative umbrella. The 5 sites are: Northwestern University Clinical Research Site (NU-CRS), Rush University Clinical Research Site (R J-CRS), and the CORE Center Clinical Research Site (CC-CRS) all located in Chicago, an international site at Fann Hospital/Universite Cheikh Anta Diop in Dakar, Senegal (SN-CRS), and the Peabody Health Center, a member of the Black Clinical Research Consortium, located in Dallas (PC-CRS). The ACTG Leadership has invited the 3 existing ACTG sites, NU-CRS, RU-CRS, and CC-CRS to participate in this recompetitive network grant. The PC-CRS is not an existing site but it has received a special invitation to participate from the ACTG Leadership for the purpose of enhancing minority patient involvement and minority research investigator development. The SN-CRS was not formally invited as only existing ACTG international sites were eligible, however this site is an NIAID/CIPRA grant awardee and a Fogarty grantee and is fully capable of performing clinical trials to NIH standards. We include them now because they are as capable of performing clinical trials as the existing international sites, they would be the only site located in West Africa, the only site with patients predominantly infected with HIV-1 subtype A/G, and the only site with a significant minority of patients infected or co-infected with HIV-2.. We believe these unique features would greatly enhance the ACTG scientific agenda. The NU-CTU is a highly productive and efficient group with an already established track record in performing multicenter, translational research and therapeutic clinical trials, ranking #1 in patient accrual and #3 in scientific productivity for the last 5 year evaluation period. We expect a seamless transition to the new structure described in this application. ADMINISTRATIVE COMPONENT: